Exchangeable crimping jaw unit

ABSTRACT

An exchangeable crimping jaw unit for fitting on to a crimping machine body to form a completed crimping machine. A plurality of heads with different crimping jaw sizes will all fit on one standard crimping machine body. Different crimping joints can be obtained merely by using different jaw units on the same body. The crimping jaws in each unit are opened and closed by means of a ram moving between the jaws. The ram in the crimping jaw unit is constructed, e.g., provided with a hook, to engage with a member for driving the ram, which said driving member is located in the crimping machine body.

United States Patent 1 Hilton Mar. 18, 1975 [54] EXCHANGEABLE CRIMPING JAW UNIT 3,571,888 3/1971 DiFilippo 29/203 H Inventor: J Leslie Hilton, Ringwood, 3,630,068 12/1971 Floyd, Jr 81/367 E gl d FOREIGN PATENTS OR APPLlCATlONS Assignee: Plessey Handel Und Investments A.G., Zug, Switzerland Prtmary Exammer C. W. Lanham Flledi 1973 Assistant ExaminerM. J. Keenan [21] APPL No; 413,414 Attorney, Agent, or Firm-Blum, Moscovitz, Friedman & Kaplan [30] Foreign Application Priority Data [57] ABSTRACT NOV. 14, United An exchangeable cr mping jaw unit for on to a crimping machine body to form a completed crimping 72/:;123l,d7:2;/74;8; machine A plurality of heads with different Crimping on one Standard ma :2 81/423 chine body. Different crimping joints can be obtained H H H merely by using different jaw units on the same body. The crimping jaws in each unit are opened and closed [56] References cued by means of a ram moving between the jaws. The ram UNITED STATES PATENTS in the crimping jaw unit is constructed, e.g., provided 2,396,562 3/1946 Forss 72/407 with a hook, to engage with a member for driving the 2,707,278 5/1955 Lindstrom 72/ 0 ram, which said driving member is located in the 3,015.824 1/1962 Richardson 72/410 i i hi b d 3,323,346 6/1967 Spangler et a1. 72/407 3,423,987 1/1969 Klingler 72/413 6 Claims, 4 Drawing Figures PATENTEB MR 1 81975 SHEH 1 BF 3 PATENTED 1 8 5 SHEET 2 o 3 lllll lllll PATENTEDHAR] 81975 3,871,224 snmsgg,

ii l-76.3.

1 EXCHANGEABLE CRIMPING JAW UNIT This invention relates to an exchangeable crimping jaw unit for a crimping machine body. The invention also relates to a crimping machine having the exchangeable crimping jaw unit positioned on a crimping machine body.

Traditionally, the joining of cable, wires and the like, e.g., telephone wires, has been manually accomplished by hand twisting. The hand twisting involves a plurality of separate operations including, for example, sliding a paper sleeve over the end of one insulated wire, bringing that wire and another insulated wire together, stripping part of the insulation, from both wires, making a prescribed number of twists in the exposed wires to join them together, cutting off excess wire, and sliding the paper sleeve back over the exposed twisted wires to insulate the joint. It will be obvious that these operations are time consuming and the consequence of operations has to be repeated as many times as there are wires, cables and the like to be jointed.

Recently, the traditional manual joining of cables, wire, and the like has been superseded by crimping machines. In these crimping machines, two or more wires, for example are joined together by a type of compression jointing known as crimping. The crimping is effected by crimping pre-insulated connectors directly on to the wires and it is not necessary to first strip off any insulation. The surplus wire ends are cut off in the crimping machine and the machine may also eject the completed. joint. As is known, the connectors generally comprise an outer plastics insulating covering and a metal conducting insert having inwardly projecting spikes which, on crimping, bite through the wire insulating covering and make electrical contact with the wires per se. Each connector in turn may be fed automatically to a position in they crimping machine in which it is ready to crimp a joint.

The crimping machines presently in use clearly present very real and significant advantages over the traditional method of hand twisting. As indicated above, the use of the crimping machine avoids the need to separately strip the wire insulation, twist the wires to be joined and cut off excess wire. The resulting crimped joint will usually be at least as effective as a hand twisted joint.

Usually, a uniform shape is required in a completed crimped joint to indicate that a uniform amount of contact has been achieved between the connector and wires. in view of this, various parts of the crimping machine have to be made to extremely close tolerances, for example down to 0.001 inch total. Even then, correct mating of the closing crimping jaws of the machine can often only be achieved by the use of shimmed adjustments determined by trial and error for each crimping machine. Such exacting requirements for the crimping machine have been acceptable where the machine is only required to produce astandard joint from standard wires or cables. However, it is often desired to connect together cables or wires of varying thicknesses or to provide crimped joints of various lengths or shapes. In these circumstances, it will be obvious that a single design of crimping jaws is not sufficient and it has hitherto been the practice to employ a separate crimping machine for each separate type of joint. It is not possible with a single crimping machine just to change the jaws to suit the type of joint required and so cable and wire jointers have been required to buy and stock a plurality of crimping machines, one for each type of joint required.

It is an aim of the present invention to overcome the above mentioned disadvantage by providing an exchangeable crimping jaw unit which can be readily attached to and removed from a crimping machine body to form a completed crimping machine. It is envisaged that various sized and shaped exchangeable crimping jaw units will be provided and will all-fit on to a single crimping maehinebody. This will give an operator a maximum choice of types of crimped joint to be made for a minimum or at least substantially reduced expenditure and amount of machine adjustment.

Accordingly, this invention provides an exchangeable crimping jaw unit for a crimping machine body, which unit comprises a pair of crimping jaws and a ram for moving the jaws towards and away from each other, said ram being constructed and adapted to be attached to a ram-driving member positioned in the crimping machine body.

Preferably, the ram continues to move towards the jaws after it has closed them, thereby to effect a compressive action in the direction of travel of the ram on a connector being crimped around a joint. Also preferably, the crimping jaw unit will incorporate a device to stop the ram travelling so far that it will strike and press against the closed jaws if a connector is not present between the closed jaws and the ram. This is because the surfaces of the jaws contacting a connector to be crimped should preferably have a smoothly polished finish to avoid damaging the connector, for example splitting its plastics insultion.

Usually, the ram will be arranged to move backwards and forwards between the crimping jaws and the crimping jaws will then be arranged to open and close in a plane at right angles to the direction of movement of a the rain. Other constructions may be employed if desired. .The ram may open and shut the jaws by means of a cammed surface. Advantageousiy, the ram is provided with an aperture and a cam is positioned in this aperture and is free to move laterally. This enables the cam to move with respect to the remainder of the ram and so centralize itself as the ram moves between the jaws. Also, the precise amount of closing of the jaws can be readily adjusted by selecting the appropriate thickness of cam.

Various arrangements may be employed to enable the crimping jaw unit to be fixed on to the crimping machine body. Thus, for example, the end of the ram remote from the jaws may be provided with an aperture 7 or the like for engaging with a hook or other attaching device in the ram-driving member. In an alternative arrangement, the end of theram remote from the jaws can be provided with a hook and the ram-driving member will then be provided with a corresponding aperture. Fixing means such, for example, as clamps can also be employed if desired.

The jaws may be spring biassed to the open position, for example by means of leaf springs. When leaf springs are employed, they may be provided with covers at their ends adjacent the crimping portion of the jaws. These covers act to prevent completed joints from failling on to the apertures created between each jaw per se and its immediate surrounding housing. Preferably, the crimping jaw unit includes wire-positioning means to position the wires to be connected in the correct position relative to the closed jaws and the connector as it is raised into the crimping position by the ram. The positioning means may be, for example, in the form of a V-groove with a central wire separator. Also preferably, the positioning means are formed as part of clamping means at either side of the jaw unit, which said clamping means can be loosened to allow the unit to slide into the crimping machine body and can then be tightened to clamp on the crimping machine body and thus facilitate the securing of the unit on the crimping machine body. One of the clamping means may be grooved at the junction of its surface with the surface of the remainder of the crimping head unit and the connectors to be crimped may be introduced through this groove.

A cutting blade may advantageously be secured to the outer face of each jaw. Thus, as the jaws more together and in co-operation with the ram effect the crimping, surplus wire is cut off.

The housing may be outwardly flared adjacent to the tops of the jaws, so that completed joints can be hitched over the lip of each flare and thus prevented from accidentally re-entering the space between the jaws when they are in the open position. Also, flared housing sides advantageously give the housing strength and rigidity.

An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings in which FIG. 1 is a top plan view ofa crimping machine in accordance with the invention, including a crimping head in accordance with the invention;

FIG. 2 is a longitudinal view, partially in section, on the line XX shown in FIGURE 1;

FIG. 3 is a view with part of the casing removed, and a partial longitudinal section on the line Y-Y shown in FIGURE 2;

FIG. 4 shows a connector that may be crimped by a crimping head in accordance with the invention.

Referring to the drawings, there is shown a crimping machine 2 comprising an exchangeable crimping jaw unit 4 and a crimping machine body 6. The exchangeable crimpingjaw unit 4 includes a housing 8 and a pair ofjaws l0, 12 which are provided in the housing 8. The pair ofjaws 10, 12 pivot about supports 14, 16 respectively which also form part of the exchangeable unit 4. Pivotting of the jaws l0, 12 about the supports 14, 16 is effected by means ofa ram 18 which again forms part of the exchangeable unit 4. The ram 18 comprises a guide portion 18A and a cam portion 18B. The cam portion 18B is a sliding fit within an aperture provided in the guide portion 18A. Thus, as the ram 18 moves between the jaws l0, 12, the cam portion 188 can position itself so that the jaws meet in correct relationship with the ram.

The jaws 10, 12 are biassed to the open position by means of two leaf springs 20, 22, forming part of the exchangeable unit 4. The ends of the leaf springs 20, 22, adjacent the jaws 10, 12, are bent over at 20A and 22A, and form protecting covers which prevent completed joints falling into the apertures created between each jaw l0, l2 and the inner adjacent surface of the housing 8.

The end of the ram 18 remote from the jaws 10, 12, is provided with an aperture 24 which receives a hook 26 projecting from a ram-driving member or slide 28. In order to enable the hook 26 to locate in the aperture 4 24, the unit 4 comprising the parts 55, 57, 60, 62, 18 and 13 are slid sideways with respect to the longitudinal direction of the machine 2 so that the steps 15 formed in the part 13, locate under corresponding steps 17 formed in a part 19 of the housing 8. The screws 105 are then tightened down and the clamping means 55, 57 press on the top of the housing 8 and so positively locate the unit 4 on the body 6. The slide 28 is causing to move backwards and forwards in the directions of the arrow 30 by means of a lever 32 which is pivotted about a movable pivot point 34 and a fixed pivot point 38. The left side of the lever 32 as viewed in FIG. 3 is connected at a pivot point 36 to a hydraulic ram 40. The ram 40 has a housing 39 and an extension piston ram member 43. The ram 40 is fixed to the housing 6 at 41. Fluid is introduced to the ram 40 by means of two fluid flow conduits 42, 44, which are connected to the ram 40 by means of connections 46, 48.

The ram 18 is also provided with a finer 50 which has a hole in it. This hole receives a spring loaded pin 52 which is fixed to the finger 50 and is provided at its upper end with a part 54 of reduced crosssection. This part 54-is adapted to project into a guide passageway 56 which receives an guides a series of loosely attached crimping connectors from a storage magazine (not shown) housed in a magazine housing 58. The part 54 further projects into the line of connectors awaiting to be crimped and prevents them from moving backwards in the passageway 56. Referring especially to FIG. 3, it will be apparent that when the ram 18 moves downwardly to allow the jaws to open, the pin 52 is also moved downwardly since it is attached to the finger 50. The part 54 is thus withdrawn from its position in the passageway 56 and the line of connectors in the passageway can then be advanced by one to place a connector to be crimped in the crimping space 56. The line ofconnectors is advanced by turning a handle 61 which causes a pawl arm and pivoted pawl 63 (FIG. 3) to rotate about a pivot 65. The pawl projects through a slot 67 in the passageway 56, engages with a line of connectors in the passageway 56 and urges them forward towards the crimping space 59 until a connector has been placed in the space 59.

The machine 2 is also provided with wire or cable guides including the separators 60, 62. A cutter blade 64, 66 is arranged one on each of the remote sides of the jaws 10, 12. The blades 64, 66 are effective to cut off the surplus ends of the wires or cables being crimped. The machine 2 is also provided with a tapped socket 150, retained by screws 152, for securing the body 6 to a crimping rail (not shown).

The operation of the crimping machine 2 in crimping two wires together is as follows. Firstly a switch is activated to connect the device 2 to a power supply. Secondly a further switch 82 is activated to energise the machine 2. Thereafter, the piston ram member 43 will move out of the housing 39 of the ram 40. Now since the piston ram member 43 is pivotted to the lever 32' at pivot point 36, the left-hand side of the lever 32 as viewed in FIG. 3 will be moved upwardly, the lever 32 pivotting about the fixed pivot point 38. As shown in FIG. 2, the pivot point 34 is constituted by a shaft 33 fixed to the slide 28. Thus, the upward movement of the left-hand side of the lever 32 causes the slide 28 to move upward and towards the jaws l0, l2 and in doing so will push the ram 18 up between the jaws 10, 12, and through the intermediate position shown in FIG. 2. As

the lever 32 moves upwards, the movable pivot point 34 (i.e., shaft 33) also moves upwardly with bearings 35 for the shaft 33 moving in guideways 37. When the cam portion 18D engages the inwardly projecting portions A and 12A of the jaws 10, 12, the jaws 10, 12 move to the closed postion in which they form a closed die, thus enabling the ram 18 to apply a compressive force to the bottom of the U-shaped connector being crimped (FIG. 5). When the fluid pressure in the machine 2 reaches a predetermined value, a pressure sensitive switch is activated and hydraulic fluid is diverted from one flow conduit 46 to the other flow conduit 48. This causes the hydraulic fluid to act on a different fact of a part of the piston ram member 43 acting within the ram 40 and causes member 43 to be retracted within the ram 40 and this causes the slide 28 to move in the opposite direction, thereby allowing the jaws 10, 12 to open under the action of the leaf springs 20, 22 and release the crimped joint.

During crimping, the guides the separators 60, 62 guide the wires to the required crimping position. Part of the connector passage 56 is constituted by a groove 56A form ed in the underside of a clamping member 57. The clamping members 57, 55 are attached to the jaw unit housing 8 by means of screws 105. These screws 105 can be loosened when the unit 2 is being placed into position on the body 6. When the unit 4 is in position, the screws 105 can be tightened and this causes the underside of the clamping members 57, 55, to grip the associated mating surfaces of the body 6. Such gripping or clamping secures the unit 2 in position on the body 6.

On the return travel of the slide 28, the switch 72 is activated by means of the roller 73 and discontinues the supply of fluid to the cylinder 40. The machine 2 is then ready to crimp another joint using another connector.

When a connector like that shown in FIGS is being crimped, the sides 91, 93 will be restrained by the dies 10, 12. The bottom 95 of the connector will be pushed upwards by the ram 18. The connector has an outer plastics covering 97 which surrounds a metal insert 99 having inwardly projecting spikes 101 on both sides 91, 93 and on the bottom 95. The spikes pierce the insulation of wires lying within the connector and make elec' trical contact with the wires per se.

The various electrical connections for the machine 2 are lead out of the machine by means of an outlet conduit 81. The fluid flow conduits 42, 44 also pass through the outlet conduit 81 and go to a hydraulic pump which operates in association with an electric motor.

The above description has been given solely by way of example and it will be obvious that various modifications can be effected in accordance with the present invention. Thus, insofar as the invention includes a whole crimping machine, it will be readily apparent that various modifications can be effected to the crimping body.

Thus, for example, the action of the ram and slide 28 need not be effected by means of the pivotting lever 32. A ram or'piston arrangement could act directly on the slide 28. Various types of geared arrangement could also be employed if desired. Similarly, with regard to the various modifications that can be effected to the head, it will be apparent that solid cable or wire separators could be employed instead of the separators 60, 62 which are formed of bent wire.

From the foregoing description, it will be realized that the crimping machine body is also novel in that it is constructed and designed to receive the exchangeable crimping jaw unit. The invention accordingly includes within its scope such a crimping machine body, i.e., one constructed and designed to receive an exchangeable crimping jaw unit in accordance with the invention.

What we claim is:

1. An exchangeable crimping jaw unit for a crimping machine body, said unit comprising in combination a pair of movable crimping jaws and a ram which moves backwards between said jaws to cause said jaws to open and close in a plane at right angles to the direction of movement of said ram, said ram being constructed and adapted to be attached to a ram driving member which is positioned in said crimping machine body and which continues to drive said ram towards said jaws after they have been closed thereby to effect a compressive action in the direction of travel of said ram, and said ram opening and shutting said jaws by means of a cam so arranged in an aperture in the ram that the cam is free to move laterally.

2. A unit as claimed in claim 1, including a stop device to stop the ram travelling so far that it will strike and press against the closed jaws if a connector is not present between said closed jaws and said ram.

3. A unit as claimed in claim 1, in which said jaws are spring biassed to the open position.

4. A unit as claimed in claim 1, including positioning means for positioning wires and the like to be crimped.

5. A unit as claimed in claim 1, including a cutter blade secured to an outer face of each said jaw.

6. A crimping machine comprising in combination an exchangeable crimping jaw unit positioned on a crimping machine body, said exchangeable crimping jaw unit comprising a pair of movable crimping jaws and a ram which moves backwards and forwards between said jaws to cause said jaws to open and close in a plane at right angles to the direction of movement of said ram, said ram being attached to a ram driving member which is positioned in said crimping machine body and which continues to drive said ram towards said jaws after they have been closed thereby to effect a compressive action in the direction of travel of said ram, and said ram opening and shutting said jaws by means of a cam so arranged in an aperture in the ram that the cam is free to move laterally. 

1. An exchangeable crimping jaw unit for a crimping machine body, said unit comprising in combination a pair of movable crimping jaws and a ram which moves backwards between said jaws to cause said jaws to open and close in a plane at right angles to the direction of movement of said ram, said ram being constructed and adapted to be attached to a ram driving member which is positioned in said crimping machine body and which continues to drive said ram towards said jaws after they have been closed thereby to effect a compressive action in the direction of travel of said ram, and said ram opening and shutting said jaws by means of a cam so arranged in an aperture in the ram that the cam is free to move laterally.
 2. A unit as claimed in claim 1, including a stop device to stop the ram travelling so far that it will strike and press against the closed jaws if a connector is not present between said closed jaws and said ram.
 3. A unit as claimed in claim 1, in which said jaws are spring biassed to the open position.
 4. A unit aS claimed in claim 1, including positioning means for positioning wires and the like to be crimped.
 5. A unit as claimed in claim 1, including a cutter blade secured to an outer face of each said jaw.
 6. A crimping machine comprising in combination an exchangeable crimping jaw unit positioned on a crimping machine body, said exchangeable crimping jaw unit comprising a pair of movable crimping jaws and a ram which moves backwards and forwards between said jaws to cause said jaws to open and close in a plane at right angles to the direction of movement of said ram, said ram being attached to a ram driving member which is positioned in said crimping machine body and which continues to drive said ram towards said jaws after they have been closed thereby to effect a compressive action in the direction of travel of said ram, and said ram opening and shutting said jaws by means of a cam so arranged in an aperture in the ram that the cam is free to move laterally. 